I currently have two small amps(20> watts), and they shoot daggers of ice at my ears when I reach high volumes. It is mainly with humbucker-equipped guitars, as my tele seems to not have this effect on them and actually sounds wonderful. Strange, considering how bright they are and are usually equated with ice picks.

Then when i plug into my 50 watt amp, the humbuckers sound magical and the tele sounds thin and like a horse's ass. What gives?

Is it per design that small amps attack you with such unpleasant sonic frequencies to punish you for not buying the premium, flagship model?

There's no particular reason why a small amp should have more treble, outside of maybe if it uses a smaller speaker/cab in a combo, or is just a cheaper practice amp voiced primarily for quieter use. If there's any correlation between size and brightness I'd guess it's incidental.

I think what you're describing is an anecdote rather than any useful or meaningful experience. The AC4 for example is supposed to be very bright. The JCA is also on the bright side of things. Their bigger counterparts aren't a whole lot darker.